Both are good engines. If you like the way a gas engine runs, get the V8, if you like the characteristics of a diesel get it. I think the differences between the two in the US is more subjective. If you want to drive 70-100+ mph routinely, the V8 may be better for you. If you want to pull 7000 lbs around town routinely, the diesel is probably better? The transmissions and drive trains are pretty much identical otherwise. There is a buy in premium for the diesel and you should ask yourself if you really need it.

 

I would think the diesel would be better for high altitude driving. I have a GMC pickup with a diesel and it drives great in the mountains. I fact it gets better miles per gallon in Rocky Mountains then driving in Kansas.

 

Gearing looks to be the same as my 70 mph rpm is the same. At low rpms the diesel should feel "peppier" as it has such abundant torque just above idle. It's all a question of whether you'll be towing (diesel) or passing (V8). Need to compare higher cost of diesel fuel vs. 87 or 89 and higher initial cost from Jeep.

 

If this helps you at all the diesel GC is slower 0-60 than the V6. Don't know the 1/4 mile but it probably just gets worse for the diesel.

V6 4x4: 7.7 sec
Diesel 4x4: 7.8 sec
Hemi 4x4: 6.6 sec
SRT: 4.1 sec

All trucks tested were 2014 with the 8 speed & 4x4. So a good comparison of engines. Yes the diesel has more torque down low than the 5.7 but it runs out of steam FAST.

If you tow or want the best MPG I'd get the diesel. But not if you want to go fast...

 

..... If you tow or want the best MPG I'd get the diesel. But not if you want to go fast...

Put well. It does seem to "go fast" off the line though, and having had the pentastar, it feels more powerful than the gasser V6 across the board to me anyway. It does run out of steam with higher rpms, but if you shift it manually and keep it in the 2-3000 rpm range, it moves along quite well under heavy throttle.

But to really get going once you are at speed, hemi is way to go, I don't think that is disputable. I wasn't willing to pay the economy penalty of the hemi for the next several years. I'm also hoping that non-commercial diesels are going to become more common and diesel prices may improve - we'll see about that.

I'm not sure if I'll get into modding the diesel, but it seems likely to have a following in the aftermarket crowd, particularly as it get more wide spread use in the Ram truck line. It'll be interesting to see what people come up with for it - seems like there is lot of potential for more power. I think we can be assured that if Banks uses this diesel for another military contract, we could really benefit. It'll also be interesting to see how mods and manufacturer restrictions on mods are balanced out.

 

If Jeep.com is accurate they have the same transmission, but different rear axle ratios. I don't know if 8HP70 means they are exactly the same in every detail. If they are it seems like they engines would have to be at different rpm's at any speed.

5.7
8HP70
3.09 Axle

3.0
8HP70
3.45 Axcle

 

good point. That seems to be the case from the website. I can't find anything on the vehicle or on the window sticker that states what the final drive ratio is. Until there is some way to decode numbers on the axle, I have to believe them.

 

The 2014 spec sheet shows the exact same transmission gear ratios regardless of engine (4.714 first, 6th is direct, .667 8th). Shift programming is likely to be different, however.

 

Another factor and one that matters more if you buy instead of leasing and keep it a long time is repair and maintenance costs. The Hemi uses a lot of gas but the performance to me is exclent and reliability has been very good at least in my experience. The only work I've done is normal maintenance (tune up) in 66K miles.
I think it's great to have the diesel option if you drive a lot. I don't so for me the Hemi is fine

 

oh boyopCorn: Yes, :google: has all the information on the HEMI.. Well my HEMI has a flux capacitor, the diesel doesn't have one of those! j/k 2013-14 HEMI is rated @ 360 HP and 390 Tq. stock, we get 14 MPG city with ours, I'm sure the diesel tows very nice and has a nice Tq. curve also and gets probably what about 18 mpgs city + or so? Have to compare the engine cost premium for both and the fuel costs too! the Diesel motor is a premium and diesel, here at least is 40-50 more per gallon too..Both are real good motors, it just depends what you plan to use it for and what you can/want afford! When towing the diesel is going to get better gas mileage then the HEMI also!

 

Found some good stuff on wikipedia:
http://en.wikipedia.org/wiki/ZF_8HP_transmission

1,2,3,4,5,6,7,8,R,Final drive
4.696,3.130,2.104,1.667,1.285,1.000,0.839,0.667,3.300,2.810

75 mph @ 1500 rpm in 8th gear.

I don't know how they can say 75mph without knowing the rear diff and I'm not sure what final drive ratio means.

Think I'm going for the HEMI though. I don't plan to tow anything heavy regularly and I think the 5.7l will be easier/cheaper to fix and modify.

 

"I think the 5.7l will be easier/cheaper to fix and modify"

Coming from being a fan of both the Hemi and the diesel and having some mod background with the diesel it is way easier and cheaper to mod. Change the injector duty cycle and boost increase is pretty common and easy to do.
However nothing sounds as good as the Hemi.
I went with the diesel strictly because I know it will pull down 28-30 interstate and over 20 in town. My former SuperDuty with 7.3L turbo pulled 17.5 to 19.1 mpg and it has the cD of a brick wall and wetted area that is huge. Also weighs 7000 pounds empty. JGC is so far ahead of my old SD and other reports seem to bare out those numbers.
Hemi is a whole lot of fun but the SRT is over the top both in performance and price.
How can you loose, you can't really...

 

Forced induction engines are almost always easier and cheaper to mod than an NA engine. There is usually a lot left on the table.